The present invention concerns a device for stretching the fabric in a weaving machine.
It is known that in a weaving machine the fabric produced between the cloth line and the place where the fabric is taken up tends to contract crosswise.
In order to avoid this concentration, a number of guide bars are provided between the cloth line and the cloth roll, which at their ends have slanting notches over equal lengths in opposite directions in order to exert and outwardly traction on the fabric. These guide bars may be situated on several places and may also serve as temple, breast beam or antifold bar.
The use of these known guide bars, however, has the disadvantage that they do not allow asymmetrical weaving over a limited width of the weaving machine, as in that case there is a greater sideward traction on one side of the fabric than on the other side, which may lead to a faulty take-up of the fabric.
A solution to this problem which allows a fabric to be made whose width is shorter than the weaving width of the weaving machine is provided by leading the fabric symmetrically over the guide bars, such that equal traction is exerted on both sides of the fabric.
However, this known method is difficult to apply in airjet weaving machines, as their main nozzle must remain as close to the fabric edge as possible and as the shift of the main nozzle according to the weft sense, for various reasons including the presence of the reed, is not always possible.
In gripper weaving machines too it is difficult to weave a fabric symmetrically having a smaller width than the weaving width of the weaving machine, because in such machines it is time-consuming or almost impossible to move the device which presents the weft thread.